Add first-class ebook request support and UI

Implements first-class ebook requests with their own type, parent-child relationship to audiobook requests, and separate status flow. Updates database schema and migrations to support 'type' and 'parentRequestId' fields on requests. Adds processors and job types for ebook search and direct HTTP download from Anna's Archive, with FlareSolverr integration for Cloudflare bypass. Enhances admin UI tables and request actions to display and manage ebook requests, including orange badge and source links. Updates documentation to reflect new ebook support, configuration, and behavior.

prisma/schema.prisma

@@ -212,7 +212,8 @@ model Request {
   audiobookId      String    @map("audiobook_id")
   status           String    @default("pending")
   // Status values: pending, awaiting_approval, denied, searching, downloading, processing, downloaded, available, failed, cancelled, awaiting_search, awaiting_import, warn
-  // Flow: pending → searching → downloading → processing → downloaded → available (when matched in Plex)
+  // Flow (audiobook): pending → searching → downloading → processing → downloaded → available (when matched in Plex)
+  // Flow (ebook): pending → searching → downloading → processing → downloaded (terminal - no available state)
   progress         Int       @default(0) // 0-100
   priority         Int       @default(0)
   errorMessage     String?   @map("error_message") @db.Text
@@ -227,6 +228,11 @@ model Request {
   updatedAt        DateTime  @updatedAt @map("updated_at")
   completedAt      DateTime? @map("completed_at")
 
+  // Request type: 'audiobook' (default) or 'ebook'
+  // Ebook requests are created automatically when an audiobook is organized (if ebook downloads enabled)
+  type             String    @default("audiobook") // 'audiobook' | 'ebook'
+  parentRequestId  String?   @map("parent_request_id") // Links ebook request to originating audiobook request
+
   // Soft delete support
   deletedAt DateTime? @map("deleted_at")
   deletedBy String?   @map("deleted_by") // Admin user ID
@@ -236,12 +242,16 @@ model Request {
   audiobook       Audiobook         @relation(fields: [audiobookId], references: [id], onDelete: Cascade)
   downloadHistory DownloadHistory[]
   jobs            Job[]
+  parentRequest   Request?          @relation("EbookParent", fields: [parentRequestId], references: [id], onDelete: SetNull)
+  childRequests   Request[]         @relation("EbookParent")
 
   @@index([userId])
   @@index([audiobookId])
   @@index([status])
   @@index([createdAt(sort: Desc)])
   @@index([deletedAt])
+  @@index([type])
+  @@index([parentRequestId])
   @@map("requests")
 }
 
@@ -260,7 +270,7 @@ model DownloadHistory {
   leechers         Int?
   qualityScore     Int?      @map("quality_score")
   selected         Boolean   @default(false)
-  downloadClient   String?   @map("download_client") // qbittorrent, sabnzbd
+  downloadClient   String?   @map("download_client") // qbittorrent, sabnzbd, direct (HTTP download for ebooks)
   downloadClientId String?   @map("download_client_id")
   downloadStatus   String?   @map("download_status")
   // Status values: queued, downloading, completed, failed, stalled
@@ -302,6 +312,7 @@ model Job {
   requestId    String?   @map("request_id")
   type         String
   // Job types: search_indexers, monitor_download, organize_files, scan_plex, plex_recently_added_check, match_plex
+  // Ebook job types: search_ebook, start_direct_download, monitor_direct_download
   status       String    @default("pending")
   // Status values: pending, active, completed, failed, delayed, stuck
   priority     Int       @default(0)